MOSCOW — Yegor K. Ligachev, the No. 2 Kremlin leader, called Wednesday for radical improvement in Soviet education to ensure the success of an effort to modernize the economy.

Ligachev, whose remarks were reported by Tass, the official Soviet news agency, spoke at a plenum of the Central Committee of the Communist Party.

Ligachev has often been labeled a conservative in comparison to his superior, Mikhail S. Gorbachev, but in his speech Wednesday, he declared that evolutionary change in the schools is unworkable.

"The Communist Party gives priority to the program of radical improvement of education," he said. " Perestroika (the program for restructuring the economy) covers the school as well. Without achieving serious change in the education system . . . we shall not be able to attain a fast pace in our constructive endeavors and make steep progress."

Politburo Changes Possible

Gorbachev is expected to address the plenum today, and changes in the makeup of the party's Politburo may be announced at the conclusion of the two-day meeting.

In his speech, party ideologist Ligachev said that the school reform program undertaken before Gorbachev took over three years ago is inadequate and based on old methods of administration. He announced two key changes.

One requires 10 years of general education for all children before they may begin specialized or vocational education. Under the present system, young people may be sent to vocational training schools after eight years of general education.

The other discontinues a program that gave schools the responsibility for training students for specific jobs.

Ligachev said the state will increase considerably its spending for capital improvements to schools, speeding the rate of construction and buying more equipment, including computers.

57 Million in School Now

He said that capital investment already amounts to nearly 40 billion rubles a year, about $66 billion at the official exchange rate.

He said that 57 million of the 280 million people in the country attend a school of some kind, and added:

"The future of the country and socialism depends on what their training will be. This is why we set the task of drastically changing guidelines for the school reform, and making the reform more radical and effective."

Not everything will be changed, he said. Soviet schools will continue to have a uniform curriculum, but more diversity in teaching methods will be encouraged.

He criticized the institutions of higher education, saying they turn out too many engineers and not enough economic managers. Although the number of establishments offering higher education has increased by 154 in the past 20 years, he said, the quality of their work has not improved.

Ligachev said that improvements are needed in Communist Party guidance of schools, to make sure that young people become "dedicated champions of revolutionary ideas and traditions."